2,793 research outputs found
Semileptonic decays of meson to S-wave charmonium states in the perturbative QCD approach
Inspired by the recent measurement of the ratio of branching fractions
to and final states at the LHCb
detector, we study the semileptonic decays of meson to the S-wave ground
and radially excited 2S and 3S charmonium states with the perturbative QCD
approach. After evaluating the form factors for the transitions , where and denote pseudoscalar and vector S-wave charmonia,
respectively, we calculate the branching ratios for all these semileptonic
decays. The theoretical uncertainty of hadronic input parameters are reduced by
utilizing the light-cone wave function for meson. It is found that the
predicted branching ratios range from up to and could be
measured by the future LHCb experiment. Our prediction for the ratio of
branching fractions is in good
agreement with the data. For decays, the relative
contributions of the longitudinal and transverse polarization are discussed in
different momentum transfer squared regions. These predictions will be tested
on the ongoing and forthcoming experiments.Comment: 12 pages, 3 figures, 5 table
3-(4-Carboxy-5-carboxylato-1H-imidazol-2-yl)pyridin-1-ium monohydrate
In the zwitterionic molecule of the title compound, C10H7N3O4·H2O, one carboxyl group is deprotonated and the pyridine N atom is protonated. The pyridinium and imidazole rings form a dihedral angle of 5.23 (1)°. An intramolecular O—H⋯O hydrogen bond occurs. In the crystal, intermolecular N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds link the zwitterions and water molecules into sheets parallel to (102)
2-(2-Hydroxy-3-methoxyphenyl)-1H-benzimidazol-3-ium perchlorate
In the title molecular salt, C14H13N2O2
+·ClO4
−, the ring systems in the cation are almost coplanar [dihedral angle = 5.53 (13)°]. Intramolecular N—H⋯O and O—H⋯O hydrogen bonds generate S(6) and S(5) rings, respectively. In the crystal, the two H atoms involved in the intramolecular hydrogen bonds also participate in intermolecular links to acceptor O atoms of the perchlorate anions. A simple intermolecular N—H⋯O bond also occurs. Together, these form a double-chain structure along [101]
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